March can still feel very wintry in Chicago, but April and May gradually bring milder weather and longer days. It is a good time to see the Route 66 starting point and walk around downtown before summer crowds arrive. Rain becomes more common as temperatures rise, so a light waterproof layer is useful. By late spring, outdoor dining and events start picking up, while conditions are generally much more comfortable for spending several hours around the city.
Summer is Chicago’s busiest travel season, and downtown can be especially active from June through August. Warm temperatures make it easy to visit the Route 66 Begin sign and spend more time walking around the city before heading west. Festivals, outdoor dining and lakefront activities are in full swing, but hotels and popular attractions can also be busier. Humidity and thunderstorms are fairly common, particularly during the hottest part of the season.
September often keeps some of summer’s warmth, while October and November become steadily cooler. The Route 66 starting point remains easy to visit, and walking around downtown is generally comfortable before colder weather settles in. Summer crowds begin to ease, although major events can still make certain weekends busy. By late autumn, jackets and warmer layers become necessary, and the first snow is possible in November, so conditions can change considerably over the course of the season.
Chicago winters are cold, windy and snowy, so visiting the Route 66 starting point requires a little more preparation. Temperatures regularly fall below freezing, and snow or ice can affect both walking and driving conditions. Downtown remains active throughout winter, particularly around the holidays, but general sightseeing is less comfortable than during warmer months. If Route 66 is part of a longer road trip, checking the forecast before leaving Chicago is sensible because winter weather can affect roads farther south too.
